Yamaha TDM 850   by Victor Wanchena

Paris to Dakar is the most grueling of all the desert races. Not even the Baja 1000 approaches the intensity of this international mad dash over rocks and sand. Few, if any, among us will ever have a chance to ride this rally, but what if you could ride a bike born out of this grand competition? Back in the early part of the nineties, Yamaha gave U.S. riders this chance with the TDM 850. The TDM grew out of Yamaha's earlier big bore dual-sport, the XTZ 750 Super Tenere (pronounced "ten-ray"). The Tenere, which was a "Europe only" bike, was developed for the Dakar rally and was aimed at competing with BMWs top selling R100GS/PD. It was a real move into the future for Yamaha with its forward angled twin, which was water-cooled and had five valves per cylinder. The motor was essentially half a sport bike four in a beefy off-road chassis complete with a half fairing and a bash guard under the motor. The bike was well received in Europe. Although, it wasn't officially exported to the U.S., some stateside rally enthusiasts lusted after it. Yamaha saw the Tenere's success in Europe in both racing and as a street bike and decided to offer a more streetable version with less suspension height and a bigger motor. Presto! The TDM 850. Brought to the U.S. in 1992, it was generally well received by the press despite their inability to classify it. Was it a street bike? Was it a dual-purpose mount? Was it a little of both? When I first saw the TDM, I was immediately taken with its height. It is not that it's overly massive; it's just that the TDM's long legs give it commanding stature, belying its dirt ancestry. The seat is approximately 33 inches off the tarmac, meaning riders much under 5'8'' will have trouble balancing at a stop. When you come around to the front of the machine the two bug eye head lamps jutting out from the bottom of the minimalist fairing jump out and say "Hi." This look is borrowed from the rally bikes and gives the TDM a very European flair. The heart of the TDM is its parallel twin motor, which is lifted from the Tenere and bored to achieve a displacement of 850cc. Parallel twins have a notorious reputation for being shakers, and this motor would be no exception were it not for the pair of counter-rotating balance shafts which quiet all but the worst vibration. Only above 6000 rpm do the vibes really seep through. Add a short stroke of 67.5 mm to a bore of 89.5 mm along with the five valves per cylinder and what does that equal? A good time. The five valves do hamper the motor below 3500 rpm, but from there to the eight grand redline, the motor pulls strongly and without fail. The real horsepower doesn't come on-line until rather late (about 6000 rpm), but that's no matter, since the meaty slabs of torque will keep you entertained. I found it no problem to loft the front wheel coming out of corners. Factory specs showed the TDM capable of pulling twelve second quarter miles at 110 mph. The transmission is a standard five-speed affair with chain final drive. It works fine, though it is a bit notchy and requires a firm, decisive pull to work smoothly. The prodigious torque makes keeping the motor in its power band all too easy. The revs hover around the 3700 mark on the freeway. Now, the frame is very undirt-like, as it's a pressed steel perimeter setup similar to the sportbikes from Yamaha of that era. The motor hangs below it as a stressed member of the chassis. This gives the bike a very firm feel, and when combined with a nice suspension setup, it keeps the bike planted on all but the worst roads. The off-road ancestry is apparent in the long suspension travel. With almost six inches of travel front and rear, the TDM can retain softer spring rates without fear of bottoming out over big bumps. The ride borders on plush, but this doesn't mean it has sloppy handling. On the contrary, the TDM steers quickly thanks to only 25 degrees of rake and can be thrown easily into corners. The height of the bike and high center of gravity does make it feel like it flops when entering a corner hard. It takes some getting used to, if a sport bike is your usual ride. A full five gallons in the fuel tank can make it really feel top heavy. The sum of all the parts equals a machine that is fun because of its flexibility. You can zip through city traffic on a bike that sits above most cars, flicking it around with the wide handlebars and stopping confidently with the twin disks up front and one in the rear. You could head out to a bent-up section of road and let it hang out on the corners. You could strap a little gear on the back and head for the open road. Or, and don't think I'm crazy, you could head off the pavement. With stock tires you're not going to go real far, but with a pair of dual-sport tires like the Avon Gripster or the Pirelli MT-70, you could really kick it up notch. I spent a week cruising around on the TDM last fall and immensely enjoyed racking up some late-season miles. Between commuting to work and a short rode trip to Mankato and back, I found few faults with the TDM. On the long trip I found the seat to be to narrow and the foam much to thin for long days in the saddle, but this could easily be cured with an aftermarket seat from Corbin or others. The mufflers keep the TDM extremely quiet. At speed on the highway you hear only mechanical noise from the engine. Very strange. After adjusting to the height of the bike, cornering held no surprises and actually inspired me to push harder into corners without fear of being upset by less than perfect road. At one point, I did venture down a couple of dirt roads and a cow path. Even with the stock tires, I found that the TDM was stable and handled most of the ruts and bumps, but don't expect to keep pace with a buddy on his new YZ250. The sad part of the story is that the TDM had dismal sales in the U.S. and lasted only two years here. Despite its popularity across the pond, U.S. buyers were not enchanted enough to lay down their money leaving many TDMs remaining on the showroom floors for a couple of years. In Europe, the bike has enjoyed continual success and the motor from the TDM even found its way into other models. This has raised the TDM to cult status with many of its owners stateside, who refuse to part with them. There are TDM clubs and a couple of web sites including the TDM List at www.interlog.com. This makes finding one for yourself rather difficult, but a few are on the market if you look hard enough. So ride the street, ride the dirt, ride what you like.   M.M.M.